Telephone-transmitter



W. AND J. BIRRELL.

TELEPHONE TRANSMITTER.

APPLICATION FILED AUG. 18, 1917. 1,342,531.

RENEWED JAN. 19

Patented June 8, 1920.

L LL H 55L n mf m m wmm m W MN M U5 i NJ UNITED. STATES PATENT omca WILLIAM BIRRELL AND JAMES BIRRELL, or CHICAGO, ILLINOIS, A SSIGNORS TO THE AUDIBLE TELEPHONE COMPANY, or CHICAGO, ILLINOIS; A CORPORATION or DELA- WARE.

Specification of Letters Patent.

TELEPHONE-TRANMITTER.

Patented June 8, 1920;

7 Application filed August 18, 1917. Serial No. 187,033. Renewed January 19, 1920. Serial No. 352,5?9,

To all whom it may concern:

Be it known that we, VILLIAM BIRnELL and JAMES BIRRELL, citizens of the United States, and residents of Chi cago,' county of 5 Cook, and State of IlllHOIS WVlIOSQ postoflice address is 170 \V. Randolph street,

have invented a new and useful Improvement in Telephone-Transmitters, of which the following is a specification. I This invention relates to improvements in telephone transmitters and more particularly to improvements in transm1tters of the type shown and descrlbed in our prlor patent application Serial No. 106,093, filed June 27, 1916.

An object of this improvement is to simplify the construction of telephone transmitters and to provide inexpenslve means for securing or fastening together the various parts of a transmitter diaphragm of the form shown in the application above referred to.

It is an important object of this invention to provide means for firmly securing an 1nsulating cover on the electrode chamber of a telephone transmitter by frlctlonal means and without the use of bolts or rivets.

The invention consists in the novel construction of a telephone transmitter and 1n 0 the novel means employed for securing certain of the parts in assembled conditlon through punching or clenching the metal of ,he peripheral edges of the electrode cham- "her over a retaining ring; S In the accompanying drawings Figure 1 is a view in vertical mid-section of a telephone transmitter constructed in accordance with this invention.

Fig. 2 is a view in sectional illustratingthe diaphragm and Fig. 3 is a detached view in elevation o the rear side of the diaphragm.

Referring to the drawings throughout which like reference numerals indicate like parts the numeral 5 indicates a telephone transmitter casing having a central threaded aperture for the reception of a mouthpiece 6 and being provided with a back plate 7 secured theretoas by screws 8 and forming a closure for a diaphragm compartment 9.

10 is a circular diaphragm loosely disposed in the compartment 9. Felt blocks 11 are arranged to prevent the displacement of the diaphragm within the compartment and perspective also act to damp and modify excessive vibra-- tions thereof. An insulating ring '12 of rubber or other suitable material encircles the periphery of the diaphragm 10. v

The diaphragm is formed With a centrally disposed electrode chamber 13 havin sitely disposed carbon electrodes 14 and 15 carried on metal disks 1 6 that are secured to the front and rear a Walls of the electrode chambers by preferably integral studs 17 and 17 all of the above mentioned devices being more specifically described in our 00- g PP pending application.hereinbefore referred to.

The novel features of the device disclosed in this application resides in the'form of construction of the electrode chamber 13,

and; themanner of securing the assembled parts intheir proper positions therein.

T he electrode chamber consists of an outer shallow recessed portion which forms an annular wall "18 and shoulder 19, and a centrally arranged deeper portion which forms the electrode chamber proper.

The shallow recessed portion is adapted for the reception of a mica insulating disk 20 which rests upon the shoulder 19 and a metal washer 21 which rests upon and holdsthe'mica disk 20.

The washer 21 is largeenough so that it fits tightly against the annular wall 18 of the shallow recessed portion and is thereby prevented from jarring loose and rattling, it being necessary to use force in seating the washer on the mica disk.

The washer 19 is securely held in place by punching or depressing the metal of the diaphragm at several points on the perimeter of the shallow'r-ecess as indicated at 22, the depressed portions being crimped securely over and caused to bear upon the edge of the washer.

In this form of construction the mica'disk and retaining washer are countersunk into the diaphragm instead of being on the rear face thereof,'and all rivets or bolts are form an electrode chamber in the diaphragmand to secure the mica disk over the elecinvention maybe resorted;- to within the 26 are wires one of which is-connect'edtothe stud 17 and-the other of which is connected with the diaphragm as by a rivet 27. I If desired the entire erimeter of the shal- 1 low recessed portion 0 thefelectrode chamber maybe clenched over'the edge of the washer 21 instead of clenching the same at a plurality'of different points as shown. The washer 21 may'also' be constructed-to'fit so "tightly in the depressed chamber that it will be frictionally held in place by. the diaphragm after being forced into position.

,It'is obvious that changes in the form 'of- 'prising an annular disk of'thin metal, a shalthe construction of the various parts-of this scope of. the appended claims; a

phra m over the edges thereon What we claim and desire to protectjby'."

Letters Patent is; I, 1. The combin tion' with a transmitter diaphragm having an electrode chamber 1 provided with a shoulder depressed' fromthe plane of-said 'diaphragim'of devices for closing said chamber adapted to reston said shoulder, said closure devices being-"held in place by clenching the metal of the diahe comb'nation with a 2. transmitter diaphragm having an electrode chamber that is provided with. a shoulder depressed from the plane ofLlsaid diaphragm, of a mica I disk adapted to close said chamber rest upon said shoulder, and a washer positioned on said mica disk, said washer being securely held in place clenchin the metal of" the diaphragm over the perip eral edgesof sa d I washer. Y

portion around the outer edge thereof that. 1 forms a shoulder and means adapted to fit within said shallow recessed portion and cessed portion around the'edge thereofthat V 3. A device of the class described com- 1 prising a metallic diaphragm having-an electrode chamber formed therein, saidelec-.

trode chamber having a shallow recessed rest upon said shoulder to close the end of said chamber said means being securely held .in position by having portions of the metalof said diaphragm clenched thereover at av plurality-of points around the edge of said electrode chamber.

4. The combination with a thin metallic plate having an integral pocket formed.

therein said pocket having a shallow. re-

forms a shoulder. of a, mica disk adapted to rest on said shoulder and close said pocket and a retaining washer within said shallow recessed portion upon said mica .disk said glean-g the. retaining riveting thej s'ame to I peripheral edges of said'washer.

' .disk, a shallow recessed portionaround said retain ng washer being adapted to fit tightly against said annular wall to prevent rattling and means 'for holding said washer said means being formed bycIenchi g portions .eter of said electrodechamber over th ipheral edge'of'said washer.

--der and within said shallowrdepres'sed por-- 'tion to close said'chamberand an-annular' ring frictionally held in the: chamber for" I retaining washer beingsecurely' held in place byele'nching the metal of said plate'over the 5. A diaphrag "for .altelephone' v mitter; comprising a' thin flexiblemetallic disk, an integral electrode chamber. in said Chamber and forming an annular wall anda shoulder,'a mica disk adapted to reston I.

said shoulder and close'said chamber, a re taining washer'positioned on said disk, said I .of the metal of said disk around-the perm-1. s

a 6. A diaphragm for a itransmi-tter .coin-' low portion depressed from theplane of said portion, depressed from :the plane. of said disk concentric to said shallow portion to form'an electrode chamber, a small diaphragin disk-adapted torest on said shoul 9O retaining washer disposed to rest on said small diaphragm disk and fit tightly within said shallow recessed portion, the: outer sur- 1 face of' said" washer bein slightly v.below' 9'5, the-plane of said annular disk and the'metal' of said annular disk being clenched over the edges of said washer at a plurality of-points; around the edge of saidshallow depressed portion to securely hold said washen-l 101 7. The "combination with a transmitter diaphragm having an electrode-chamber dej-' pressed from the plane thereof, of an in- 'T sulating disk: in the chamber and a metal securing the insulating disk in position:

8. The combination w'ith ,a thin metallic plate 'having an integral, pocket formedtherein anda shoulder formed around the 1 edge of said pocket of insulating -means 11( adapted to rest on said shoulder and. close said pocket, and frictionally secured retain-" ing means for holding the insulating means 'inplace. 4 Y

9. A device of the class described 'coinpris 11 l ing a metallic diaphragm, a central cylindrical chamber depressedfrom the plane'of I V diaphragm, a second chamber integral with and of less diameter than the first mentioned chamber, and insulating means secured in 121 first chamber to close the second chamber.

"Signed at Chicago, Illinois, on the 14th day of Aug, 1917. 1 I

WILLIAM BIRRELL, JAMES BIRRELL; 

